Field of the Invention
The invention is directed to a display apparatus and more particularly, to a display apparatus, a gate driver and an operation method thereof.
Description of Related Art
FIG. 1 is a schematic diagram illustrating an equivalent circuit of a display panel in the related art. A display panel 110 has a plurality of source lines 111, a plurality of gate lines 112 and a plurality of pixel circuits 113. The source lines 111 are perpendicular to the gate lines 112. The pixel circuits 113 are distributed in an array on the display panel 110. Source terminals of the pixel circuits 113 are respectively coupled to the corresponding source lines 111, and gate terminals of the pixel circuits 113 are respectively coupled to the corresponding gate lines 112, as illustrated in FIG. 1.
A plurality of output terminals of a gate driver 120 are one-to-one coupled to different gate lines 112. The gate driver 120 may takes turn to drive (or scan) each of the gate lines 112 of the display panel 110 one by one. A source driver 130 converts a plurality of digital pixel data into corresponding driving voltages (pixel voltages). Based on a scanning sequence of the gate driver 120, the source driver 130 write the corresponding pixel voltages into the corresponding pixel circuits 113 of the display panel 110 through the source lines 111.
A plurality of parasitic capacitors 114 exist between the source lines 111 and the gate lines 112. In the process of the source driver 130 writing the driving voltages (pixel voltages) into the pixel circuits 113 through the source lines 111, AC components of the driving voltages of the source lines 111 are transmitted to the gate lines 112 through the parasitic capacitors 114. AC components of the driving voltages of the source lines 111 are transmitted to the gate driver 120 through the gate lines 112, and generate coupling noise of the gate driver 120. The coupling noise influences different internal signals in the gate driver 120 through a substrate or a body of the gate driver 120, and may even influence a ground voltage inside the gate driver 120.
FIG. 2 is a schematic waveform diagram of the source lines 111 and the gate lines 112 depicted in FIG. 1. In FIG. 2, the horizontal axis represents the time, and VCOM represents a common voltage of the display panel 110. When the source driver 130 outputs a specific image (in a specific pattern) to the source lines 111 of the display panel 110, the voltages of several (even all of) the source lines 111 may simultaneously rise up or drop down, such that the coupling noise (as illustrated in FIG. 2) occurs in the signals of the gate lines 112. The coupling noise enters the gate driver 120 through the gate lines 112.